Vertebrae: Thoracic

The vertebral column can be intimidating. However, there are similarities in all the vertebrae. There are also similarities among those in specific locations.  We start at the bottom, or inferiorly. Here, we have the sacrumTriangular bone formed by fusion of five vertebrae; connects spine to pelvis. and the coccyxTailbone; small, fused vertebrae at the end of the sacrum.. These were discussed in another video with the os coxa or the hips.  Just above, or superiorAbove or toward the upper part of the body. to the sacrum are the lumbar vertebraeLargest and thickest vertebrae; short, blunt spinous processes for weight-bearing stability. in yellow here.  We number them top to bottom, so sorry I started at the bottom.  L1 is the most superior lumbar vertebra down to the L5 vertebra.  These are separate bones, whereas the sacrum and coccyx were fused bones.  These lumbar bones have discs made of fibrocartilageA tough, shock-absorbing cartilage found in intervertebral discs and menisci. that act as cushions.  Moving on up.  The thoracic spineProminent ridge on the posterior scapula dividing it into supraspinous and infraspinous fossae. is considered your chest vertebra and there are 12 of those.  The cervical vertebraeSmallest vertebrae; have transverse foramina for vertebral arteries; often bifid spinous processes. are the neckNarrow region just below the head; common fracture site. vertebrae and there are 7 of those.  But, the top two have their own names.

Let’s do some anatomyThe study of the structure of the human body. of these bones.  Ug.   I know.  As we do this, let’s really take a hint from what the names are telling us.  Starting with the transverse process.  It’s a process, that sticks out to the side.  Seriously.  You can see it well on the atlasFirst cervical vertebra; ring-shaped, no body; supports the skull at the occipital condyles (“yes, not so much on the axisSecond cervical vertebra; has the odontoid process (dens) for pivoting head (“no” motion)..  Those cups that we saw that the skull rocks on are called the superior articular facets.  They are on the superior side of the vertebra.  They articulate with the vertebra above.  And they are little cups.  That’s what a facet is.  So, we have a process and a facet.

This would be the transverse foramenOpenings in cervical vertebrae for vertebral arteries; unique to cervical region.. Hole to the side. The big hole in the center is the vertebral foramenCentral hole in each vertebra where the spinal cord passes through..  This vertebral foramen is always the center; it’s where the spine threads through.  This spike here is the spinous processPosterior projection from vertebral arch; palpable bumps down the back..  This will always jut out to the posterior or back.  Ok, so, take a moment to orient your self.  The back of the vertebra is at the top of the picture.  The front, or anteriorThe front of the body or toward the front when standing in the anatomical position., of the vertebra is at the bottom of the picture.  Ooooh.

Thoracic vertebra are always used as the model vertebra when studying bones.  Usually the first thing you look at with a vertebra is the hole in the center.  Cervical vertebra had triangular vertebral foramen, but thoracic vertebraeHeart-shaped body, long downward spinous process, and facets for rib attachment. have nice and round vertebral foramen.  Remember, these are chest vertebrae and they articulate with the ribsCurved bones forming the rib cage; articulate with thoracic vertebrae and most with the sternum..  Here again, is our transverse process. It sticks out to the side. It has a little cup to connect to a rib.  What is this???  You know what it is.  It is the, say it with me, superior articular facetSmooth, flat surface on the upper side of a vertebra for articulation with the vertebra above..  It’s a little cup that connects with the bone above.  And we have a new feature called the body.  As we move inferiorly down the vertebral column, the vertebra get thicker and thicker to handle the weight.  So, we will see this body get thicker.

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